New Delhi, Jan 16 (IANS): The national capital on Thursday morning witnessed fog with the air quality recorded under 'poor' category, along with light showers in various parts of Delhi and adjoining areas.

The minimum temperature was recorded at nine degrees Celsius, an IMD official said.

"The maximum temperature, however, is likely to hover around 21 degrees Celsius," the official added.

The sky will be generally cloudy with thunderstorm with hail expected during the day, the official informed.

At least 12 Delhi-bound trains were delayed by several hours on Thursday due to fog, railway officials said.

The air quality of the national capital was recorded under 'poor' category.

According to the Centre-run System of Air Quality and Weather Forecasting (SAFAR), the overall air quality index (AQI) of Delhi was recorded at 245.

Improvement in AQI is due to the "influence of approaching western disturbance, increased wind speed and fairly widespread precipitation," SAFAR said.

The Air quality Index may deteriorate slightly on Friday "but will remain within upper end of moderate to poor category," it added.